[clang] Objective C: use C++ exceptions on MinGW+GNUstep (PR #77255)

[David Chisnall via cfe-commits]

davidchisnall wrote:

It looks as if three tests are failing in CI:

  Clang :: CodeGenObjC/2007-04-03-ObjcEH.m
  Clang :: CodeGenObjC/exceptions-personality.m
  Clang :: Coverage/codegen-gnu.m


https://github.com/llvm/llvm-project/pull/77255